VorbisGain is a utility that uses a psychoacoustic method to correct the
volume of an Ogg Vorbis file to a predefined standardized loudness.
It is meant as a replacement for the normalization that is commonly used
before encoding. Although normalization will ensure that each song has the
same peak volume, this unfortunately does not say anything about the apparent
loudness of the music, with the end result being that many normalized files
still don't sound equally loud. VorbisGain uses psychoacoustics to address
this deficiency. Moreover, unlike normalization, it's a lossless procedure
which works by adding tags to the file. Additionally, it will add hints that
can be used to prevent clipping on playback. It is based upon the ReplayGain
technology.